In a show of solidarity, staffers at Competitor Group in Mira Mesa came to work here after the Boston Marathon wearing a variety of colorful marathon, half-marathon, 5-K and Chelsea King Run race jerseys.

The company publishes Competitor Magazine and runs the Rock ’n’ Roll marathon series. Its employees had launched a “Runners Unite” initiative — an impromptu grass-roots display of pride and tribute. Senior VP Tracy Sundlun even flew home from Boston wearing his Providence marathon shirt under a blue blazer. He was one of 14 Competitor Group staffers working the Boston race. Two ran in it but didn’t see the explosions.

The bombings won’t discourage runners from competing, Sundlun said. “Probably the opposite. Distance runners are an amazingly resilient, tough, achieving group who challenge themselves and love their freedom to be able to go out and run on their own terms. They won’t back off.”

Rock ’n’ Roll organizers, meanwhile, are busy reviewing security measures with Tennessee officials for their marathon in Nashville next week. Sundlun said there’s been no indication of participants dropping out.

His colleague, Dan Cruz, who had left the finish line area about 10 minutes before the bombs detonated, noted: “We’ve seen a strong outpouring of support on our Facebook pages.” One runner wrote that she was wearing her race jersey to work under her suit.

Toni Reavis, who, before moving to San Diego, lived in Boston and has done broadcasts of the marathon since 1977, said the finish line area is normally totally cleaned up by day’s end. Not this one, though. Everything — trash, bomb debris, bleachers, — was left as it was. “The whole area was a crime scene.”

Romney appears: Tagg Romney. oldest son of GOP presidential candidate Mitt and Ann Romney, who have a home in La Jolla, showed up at the site from a nearby Red Sox game. Tagg lives in Boston, where he runs an investment firm. He told CNN: “They messed with the wrong people.”